The effect of UV radiation on the human lens was previously considered negligible due to the corneal absorption of radiation below 300 nm. However, this corneal cut off is not sharp and the small amount of UV radiation and the significant levels of near UV radiation transmitted through the corneal epithelium and stroma have been implicated as a cause of so-called brunescent or brown cataracts in the aged. Conditions such as: 1) prolonged, cumulative exposure to UV radiation; 2) abnormally high dosage of UV radiation, and 3) nutritional defects or excesses that sensitize cataractogenesis, have net been specified, even though they tend to contribute to general lens opacification. In determining these environmental, occupational (or industrial) and nutritional safety parameters, one must have understanding of how (and under what conditions) radiation in the UV/near UV initiates the molecular level changes that eventually lead to lens opacification. The proposes research is aimed at elucidating the role of chromophores in the lens proteins and peptides in the photoinduced, catatactogenic crosslinking and aggregation of peptides, via photoacoustic spectroscopy (PAS). The application of photoacostic detection to the optical spectroscopy of lens tissue avoids the inherent problem of light scattering (especially in the opacified lenses) and enables researchers to obtain important molecular parameters not previously obtainable by conventional transmission spectroscopy.